Rena RyuuguThe first shiny legendary I went for was Latias in Omega Ruby. It ended up fainting due to struggle. So I'm happy to have a shiny Groudon as it's one shiny I wanted for years. I end up catching any shiny I come across at full health as I don't want it to faint.

I found that it helps having something on in the background when SRring, was halfway through Star Wars when shiny Groudon appeared.